Abstract: Several analytical, numerical and experimental techniques are available to study the stress concentration around the notches. The stress distribution in a rectangular composite laminated plate with a central notch was studied using the finite element method. The objective of this study is to analyze the fibre orientation effect on the variation of stress concentrations at the notch root and the J-integral at the crack-tip emanating from this notch in a plate subjected to tensile loading. The results show that the anisotropic stress concentration factor can be higher or lower than that of a homogeneous material. The area of maximum normal and tangential stresses could shift with fibre orientation with respect to the loading axis. The interaction effect between a crack located on the ligament of the plate and the circular notch of radius is considered.The results indicate that fold sequence influences appreciably the acceleration or the retardation of the crack propagation.

Abstract: FEM linear numerical analysis of stress distribution demonstrated that the model Zappalorto and Lazzarin for analysed V-hole ended notch, relatively correctly predicts the stress distribution at the tip of the notch, especially for small angles of opening. The maximum levels of hoop stress and a tangential for load Mode II strongly dependent on the radius of the notch. The stress reaches its maximum value at a certain distance from the tip of the notch, approximately equal to half of the hole circle radius. The most effective way to reduce the levels of maximum stress at the notch is to increase the radius. When changing radius of 0.5 mm to 2 mm can reduce the degree of stress concentration approx. 40%.